Musk believes that by hitting Mars with nuclear weapons, the planet’s polar ice caps could melt and release vast amounts of carbon dioxide into the atmosphere, which would essentially create a greenhouse effect that raises the temperature and air pressure of the planet — like a really quick version of climate change.

Musk has shared this opinion for years, dating back to interviews with the billionaire from 2015. He even went on Stephen Colbert’s late-night talk show to discuss his idea to bomb Mars — it starts around the 2-minute mark: